# Brakes malfunction when cold **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** nissan, sentra, brakes\ **Created:** [March 14, 2018, 10:16pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704 "2018-03-14T22:16:43Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Austin\_II](https://avatars.discourse-cdn.com/v4/letter/a/258eb7/32.png) [@Austin\_II](https://community.cartalk.com/u/Austin_II)\ **Post date:** [March 14, 2018, 10:16pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/1 "2018-03-14T22:16:43Z")
2016 Sentra. Brake pedal sometimes has to be pushed very hard when first starting in the AM and still barely stop the car. After pumping a couple of times, usually they are OK. Nissan dealer and personal mechanic couldn’t recreate the problem and said everything checks out. Anyone had this problem or have thoughts on what the problem might be? ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [March 14, 2018, 11:11pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/2 "2018-03-14T23:11:13Z")
If no one is familiar with that specific problem on a Nissan I suggest you try driving shoeless to see if the problem vanishes or if you recognize that something is interfering with your foot. On several occasions a drivers complaint of unintended acceleration turned out to be their foot inadvertently pressing both the brake and accelerator. ---
**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\ **Post date:** [March 14, 2018, 11:30pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/3 "2018-03-14T23:30:29Z")
> [@Austin\_II](#): > > 2016 Sentra. Brake pedal sometimes has to be pushed very hard when first starting in the AM and still barely stop the car. After pumping a couple of times, usually they are OK. Nissan dealer and personal mechanic couldn’t recreate the problem and said everything checks out. Anyone had this problem or have thoughts on what the problem might be? Dd you check your carpet or mat for interference with the pedal? ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [March 15, 2018, 1:22am UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/4 "2018-03-15T01:22:13Z")
A problem with the brake booster or its vacuum supply is a possibility. Ask your shop to test the ability of the brake booster and it’s vacuum lines to hold vacuum. They may need to park the car on their lot overnight so they can test it first thing in the AM when it is cold. The rubber parts can become stiff and leak vacuum. As long as there’s no interference found at the brake pedal itself, that’s where I’d start anyway. ---
**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\ **Post date:** [March 15, 2018, 1:30am UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/5 "2018-03-15T01:30:07Z")
> [@George\_San\_Jose1](#): > > A problem with the brake booster or its vacuum supply is a possibility. Ask your shop to test the ability of the brake booster and it’s vacuum lines to hold vacuum. They may need to park the car on their lot overnight so they can test it first thing in the AM when it is cold. The rubber parts can become stiff and leak vacuum. As long as there’s no interference found at the brake pedal itself, that’s where I’d start anyway. I doubt the rubber parts have deteriorated significantly since this is a 2016 car. However, I think you may be on the right track. Maybe water in a vacuum line that freezes overnight? ---
**Author:** ![Austin\_II](https://avatars.discourse-cdn.com/v4/letter/a/258eb7/32.png) [@Austin\_II](https://community.cartalk.com/u/Austin_II)\ **Post date:** [March 15, 2018, 12:50pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/6 "2018-03-15T12:50:58Z")
Thanks for the suggestion. > > NYBo > > March 15 | [quote=“George\_San\_Jose1, post:4, topic:113704, full:true”] A problem with the brake booster or its vacuum supply is a possibility. Ask your shop to test the ability of the brake booster and it’s vacuum lines to hold vacuum. They may need to park the car on their lot overnight so they can test it first thing in the AM when it is cold. The rubber parts can become stiff and leak vacuum. As long as there’s no interference found at the brake pedal itself, that’s where I’d start anyway. [/quote]I doubt the rubber parts have deteriorated significantly since this is a 2016 car. However, I think you may be on the right track. Visit Topic or reply to this email to respond. In Reply To > > George\_San\_Jose1 > > March 15 | A problem with the brake booster or its vacuum supply is a possibility. Ask your shop to test the ability of the brake booster and it’s vacuum lines to hold vacuum. They may need to park the car on their lot overnight so they can test it first thing in the AM when it is cold. The rubber parts can… Visit Topic or reply to this email to respond. To unsubscribe from these emails, click here. ---
**Author:** ![Austin\_II](https://avatars.discourse-cdn.com/v4/letter/a/258eb7/32.png) [@Austin\_II](https://community.cartalk.com/u/Austin_II)\ **Post date:** [March 15, 2018, 1:04pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/7 "2018-03-15T13:04:34Z")
Yes - it’s not a mat issue or something else interfering. I bought the car new in 2015 and had no problem with it until recently. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [March 15, 2018, 1:48pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/8 "2018-03-15T13:48:19Z")
Does it get below freezing where you are, and do you park it in a garage? Under the right conditions water can get into the brake booster vacuum system as the car slowly cools in the garage. Then you drive it to work and it sits out all day in the freezing weather, and the water freezes and makes the one-way valve stick. If you hammer on the brake pedal with your foot really hard, it’s usually enough to break the ice. The long-term solution is to take off the booster hose and then thoroughly dry everything out. If the problem returns, replace the check valve. ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [March 15, 2018, 2:22pm UTC](https://community.cartalk.com/t/brakes-malfunction-when-cold/113704/9 "2018-03-15T14:22:31Z")
And easily overlooked place for ice to cause the problem is at the push rod. There is a vent at the floor around the push rod and there is a foam filter there that can become a problem.